Cost Not the Only Obstacle to Moving Tulsa Power Lines Underground

Aug 27, 2013

Mayor Dewey Bartlett and the Tulsa City Council made exploring underground utility placement a goal for 2013. It's one that became more important after thousands lost power for days following July storms.

But in a presentation to city councilors, representatives of Public Service Company of Oklahoma showed there's much more to consider than the price tag of moving power lines underground.

Perhaps the most meaningful conversation so far about moving Tulsa's electric utilities underground happened in an alleyway off Second Street between Detroit and Elgin avenues. It's arched with aging wooden H-frames that carry aging power lines.

As electric blues piped through the patio speakers of a nearby restaurant, the handful of city councilors in attendance ask questions about — well, Tulsa's own electric blues. 

The cost of converting to underground lines is a primary concern. PSO executive Steve Baker laid out the cost per mile.

"Without excavation costs included, it can range from $600,000 to a million and a half," he said.

Overhead lines are much cheaper.

"It's a fraction. You know, it's a third or a fourth of the costs," Baker said.

District One Councilor Jack Henderson learned taking power lines underground won't be a silver bullet against outages like those caused by July's storms.

"Even areas like Gilcrease, where all of theirs are underground, some transformer down the road that feeds that gets out, and then we can still lose our power. But it's easy to get back on, though, right?" Henderson asked PSO engineer George Heady.

"It was amazing, in our last storm. I'd never seen a three-phase, pad-mount transformer, which is about this big, this tall — the wind blew it over," Heady said, using his hands to indicate roughly the size of a smart car. "So those guys were out for, like, a day and a half because of all the work you have to get.

"You've got to get cranes and do all this other work. And what happened is this big wood fence by it, that wood fence just acted like a sail and just blew it," Heady said.

Heady also answered a question from District Two Councilor Jeannie Cue.

"Do you feel underground is the safer way, in the future?" Cue asked.

"The issue I have with underground is the digging you have to do. So many people will dig into it," Heady said. "The law says you've got to call 800 locates to get it located before you go dig, but a lot of people dig without that, and that's one of the hazardous parts right there."

As the presentation went on, city councilors learned the host of issues with taking power lines underground. Those issues may not make underground lines worth the increased cost.

Underground lines can be extremely difficult to install in older areas of Tulsa. Baker pointed to the alley as a perfect example.

"You put that under here, there's no telling what's underneath here. There's been 100 years worth of development here, so we've run into things like storage tanks, and foundations, and landfills and environmental issues — all sorts of things," Baker said.

And once the lines are in the ground, maintenance is tougher.

"Something you can see overhead, if you're trying to repair the system, [is] much easier to see — I mean, repair it, if you can see where it's fed from and where it is, versus underground, you're relying on maps, and you'll have to open up the ground to find the cable or what the problem might be," Baker said. "In general, it's longer to troubleshoot and repair underground than it is overhead."

But that's all assuming PSO can get everyone else with overhead lines on board. Telephone, fiber optic and cable TV lines run along city utility poles, too.

"It wouldn't just be an electric system project," Baker said. "It would be everybody that's currently overhead, and all the stuff that's underground, all those parties, all those owners of those facilities would need to participate."

As utility representatives removed their diagrams from the decades-old brick walls, it was unclear whether the notion of moving Tulsa's power lines underground will stick around.

The mayor and the council have no plans right now past exploring the possibility. PSO at least gave them plenty of information to work with.